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MEASUREMENT
Measurement
“If you can’t measure it, you can’t manage it.”
Bob Donath, Consultant
Measurement
Selecting measurable phenomena
Developing a set of mapping rules
Applying the mapping ruleto each phenomenon
What is to be measured?
CONCEPTS/CONSTRUCTS/VARIABLES
Operational DefinitionsOperational Definitions- Dimensions- Dimensions- Elements- Elements
ScalesScales
CONCEPT
A GENERALIZED IDEA ABOUT A A GENERALIZED IDEA ABOUT A CLASS OF OBJECTS, CLASS OF OBJECTS,
ATTRIBUTES, OCCURRENCES, ATTRIBUTES, OCCURRENCES, OR PROCESSES.OR PROCESSES.
(e.g., (e.g., Technology, Dynamism, Adoption, Technology, Dynamism, Adoption, Learning)Learning)
CONSTRUCT
An image or idea specifically invented for a given An image or idea specifically invented for a given research and/or theory-building purposeresearch and/or theory-building purpose
Higher level concepts for specialised scientific Higher level concepts for specialised scientific explanatory purposes that are not directly explanatory purposes that are not directly observable and for thinking about and observable and for thinking about and communicating abstractionscommunicating abstractions
Concepts and constructs are used at theoretical levels Concepts and constructs are used at theoretical levels
VARIABLE
Used at empirical levelUsed at empirical level Accept numeral or values for the purpose of Accept numeral or values for the purpose of
testing and measurementtesting and measurement
OPERATIONAL DEFINITION
A definition for a construct stated in terms of A definition for a construct stated in terms of specific criteria for testing or measurementspecific criteria for testing or measurement
Specifies what the researcher must do to Specifies what the researcher must do to measure the concept/construct under measure the concept/construct under
investigationinvestigation
SCALE- Definition
SERIES OF ITEMSSERIES OF ITEMS ARRANGED ACCORDING TO VALUEARRANGED ACCORDING TO VALUE FOR THE PURPOSE OF FOR THE PURPOSE OF
QUANTIFICATIONQUANTIFICATION A CONTINUOUS SPECTRUMA CONTINUOUS SPECTRUM
SCALE PROPERTIES
UNIQUELY CLASSIFIESUNIQUELY CLASSIFIES PRESERVES ORDERPRESERVES ORDER DISTANCE/EQUAL INTERVALSDISTANCE/EQUAL INTERVALS NATURAL ORIGIN (ZERO)NATURAL ORIGIN (ZERO)
Types of Scales
OrdinalOrdinal
IntervalInterval
RatioRatio
NominalNominal
NOMINAL SCALE
Nominal Scales
Mutually exclusive Mutually exclusive and collectively and collectively exhaustive exhaustive categoriescategories
Exhibits the Exhibits the classification classification characteristic onlycharacteristic only
NOMINAL SCALE PROPERTIESUNIQUELY CLASSIFIESUNIQUELY CLASSIFIES Male/FemaleMale/Female Academic/AdminAcademic/Admin Asian/EuropeanAsian/European Strategy typesStrategy types Adopters/Non AdoptersAdopters/Non Adopters
Levels of Measurement
OrdinalOrdinal
IntervalInterval
RatioRatio
NominalNominal ClassificationClassification
ORDINAL SCALE
Ordinal Scales
Characteristics of Characteristics of nominal scale plus nominal scale plus an indication of an indication of orderorder
Implies statement Implies statement of greater than and of greater than and less thanless than
ORDINAL SCALE PROPERTIES
UNIQUELY CLASSIFIESUNIQUELY CLASSIFIES
PRESERVES ORDERPRESERVES ORDER Win, Place & ShowWin, Place & Show Podium/Grid positionsPodium/Grid positions RankingRanking
Levels of Measurement
OrdinalOrdinal
IntervalInterval
RatioRatio
NominalNominal ClassificationClassification
OrderOrderClassificationClassification
INTERVAL SCALE
Interval Scales
Characteristics of Characteristics of nominal and ordinal nominal and ordinal scales plus the scales plus the concept of equality concept of equality of interval. of interval.
Equal distance Equal distance exists between exists between numbersnumbers
INTERVAL SCALE PROPERTIESUNIQUELY CLASSIFIESUNIQUELY CLASSIFIES
PRESERVES ORDERPRESERVES ORDER
EQUAL INTERVALSEQUAL INTERVALS Consumer Price Index (Base 100)Consumer Price Index (Base 100) Fahrenheit TemperatureFahrenheit Temperature Assessment of attitude, beliefs, intentionAssessment of attitude, beliefs, intention
Levels of Measurement
OrdinalOrdinal
intervalinterval
RatioRatio
NominalNominal ClassificationClassification
OrderOrderClassificationClassification
OrderOrderClassificationClassification DistanceDistance
RATIO SCALE
Ratio Scales
Characteristics of Characteristics of previous scales plus an previous scales plus an absolute zero pointabsolute zero point
ExamplesExamples WeightWeight HeightHeight Number of childrenNumber of children
RATIO SCALE PROPERTIES
UNIQUELY CLASSIFIESUNIQUELY CLASSIFIES
PRESERVES ORDERPRESERVES ORDER
EQUAL INTERVALSEQUAL INTERVALS
NATURAL ZERONATURAL ZERO Weight and distanceWeight and distance Age, years of serviceAge, years of service
Levels of Measurement
OrdinalOrdinal
IntervalInterval
RatioRatio
NominalNominal ClassificationClassification
OrderOrderClassificationClassification
OrderOrderClassificationClassification DistanceDistance
Natural OriginNatural Origin
OrderOrderClassificationClassification DistanceDistance
Goodness of Measures
Accurately measuring what Accurately measuring what actually the concept one sets out to actually the concept one sets out to measuremeasure
Should be easy and efficient to useShould be easy and efficient to use
Evaluating Measurement Tools
CriteriaCriteria
Validity
Practicality ReliabilityReliability
Validity
The ability of a scale to measure The ability of a scale to measure what was intended to be what was intended to be
measured.measured.
Validity Determinants
Content
ConstructCriterion
Increasing Content Validity
ContentLiterature Search
Literature Search
Expert Interviews
Expert Interviews
Group Interviews
Group Interviews
Question DatabaseQuestion Database
……Goodness of Measures
ValidityValidity Content Validity Content Validity
Includes Face ValidityIncludes Face ValidityHow well the dimensions and elements How well the dimensions and elements
of a concept have been delineatedof a concept have been delineatedProfessional agreement that a scale Professional agreement that a scale
logically appears to accurately measure logically appears to accurately measure what it is intended to measure what it is intended to measure
Validity Determinants
Content
Construct
Increasing Construct Validity
New measure of trustNew measure of trust
Known measure of trustKnown measure of trust
EmpathyEmpathy
CredibilityCredibility
……Goodness of Measures
Construct Validity – when empirical evidence Construct Validity – when empirical evidence generated by a measure is consistent with the generated by a measure is consistent with the theoretical logic of the concept theoretical logic of the concept
Convergent Validity – the measure should Convergent Validity – the measure should “converge” with other similar measures“converge” with other similar measures
Discriminant Validity – when the measure Discriminant Validity – when the measure has low correlation with measures of has low correlation with measures of dissimilar conceptdissimilar concept
Judging Criterion Validity
RelevanceRelevance
Freedom from biasFreedom from bias
ReliabilityReliability
AvailabilityAvailability
Criterion
Criterion-Related Validity
Concurrent – When the scale discriminates Concurrent – When the scale discriminates individuals who are known to be different; A individuals who are known to be different; A type of criterion validity whereby a new type of criterion validity whereby a new measure correlates with a criterion measure measure correlates with a criterion measure taken at the same time.taken at the same time.
Predictive Validity – Ability to differentiate Predictive Validity – Ability to differentiate among individuals with reference to a future among individuals with reference to a future criterioncriterion
VALIDITY
F A C E O R C O N TE N T
C O N C U R R E N T P R E D IC TIV E
C R ITE R IO N V A L ID ITY C O N S TR U C T V A L ID ITY
V a lid ity
Reliability
The degree to which measures are The degree to which measures are
free from random free from random errorerror and and therefore yield consistent results.therefore yield consistent results.
Reliability Estimates
Stability
InternalConsistency
Equivalence
Reliability Estimates
Stability
InternalConsistency
Equivalence
Stability of MeasuresStability of MeasuresTest-Retest Reliability – the Test-Retest Reliability – the
administering of the same scale or administering of the same scale or measure to the same respondents at two measure to the same respondents at two separate points in timeseparate points in time
Parallel-Form Reliability - when Parallel-Form Reliability - when responses on two comparable sets of responses on two comparable sets of measures tapping the same construct are measures tapping the same construct are highly correlatedhighly correlated
… Reliability
Reliability Estimates
Stability
InternalConsistency Equivalence
Equivalence
Variations at one point in time among Variations at one point in time among observers and samples of itemsobservers and samples of items
Reliability Estimates
Stability
InternalConsistency
Equivalence
… Reliability
Internal Consistency MeasuresInternal Consistency MeasuresInteritem Consistency Reliability - Interitem Consistency Reliability -
where items that are independent where items that are independent measures of the same concept correlate measures of the same concept correlate with one another.with one another.
Split-Half Reliability – reflects the Split-Half Reliability – reflects the correlations between two halves of an correlations between two halves of an instrument instrument
RELIABILITY
TE S T R E TE S T
S TA B IL ITY
E Q U IV A L E N T F O R M S S P L ITTIN G H A L V E S
IN TE R N A L C O N S IS TE N C Y
R E L IA B IL ITY
Understanding Validity and Reliability
Practicality
Economy InterpretabilityConvenience
SENSITIVITY
A measurement instrument’s ability to A measurement instrument’s ability to accurately measure variability in accurately measure variability in stimuli or responses.stimuli or responses.
Rating ScalesUsed to elicit responses with regard to the object, event, or person studies:
Dichotomous scaleDichotomous scale
Category scaleCategory scale
Likert scaleLikert scale
Numerical scaleNumerical scale
Semantic differential scaleSemantic differential scale
…..Rating Scales
Itemised rating scaleItemised rating scale
Fixed or constant sum rating scaleFixed or constant sum rating scale
Stapel scaleStapel scale
Graphic rating scaleGraphic rating scale
Consensus scaleConsensus scale
Ranking ScalesTo tap preferences between two or more objects or items
Paired ComparisonPaired Comparison
Forced ChoiceForced Choice
ComparativeComparative